Dental plugger



(No Model.)

J. L. MEWBORN.

vDENTAL PLUGGER.

No. 443,399. Patented Dec. 23,-1'890.

INVENTO? -ff/5 l.

A TTOHNEYS tion of the same.

UNITED STATES i PATENT OFFICE;

JOSEPH L, MElVBORN, OF MEMPHIS, TENNESSEE.

DENTAL PLUGGER.

SPECIFICATION forming part 0f Letters Patent No. 443,899, dated December 23, 1890.

Application led February '7, 1890. Renewed November 21, 1890. Serial No. 372,149. (No model.)

T0 all whom it may concern:

Be it known that l, JOSEPH L. MEWBORN, of Memphis, in the county of Shelby and State of Tennessee, have invented a new and Improved Machine-Mallet, of which the following is a specification, reference being had to the annexed drawings, forming a part thereof, in which Figure l is a side elevation of my improved machine-mallet. Fig. 2 is a longitudinal sec- Fig. 3 is a transverse section taken on line 3 3 in Fig. 2. Fig. 4 is a transverse section taken on line 4 4 in Fig. 2. Fig. 5 is a detail view of the mallet-operating cam, and Fig. 6 is a side elevation of the dental plugging-tool.

Similar letters of reference indicate corresponding parts in all the views.

I shall describe my improved machin e-m allet as applied to dental operations; but I do not limit or confine myself to this use, as it may be employed in surgery, in carving, engraving, and other mechanical operations.

The object ol' my invention is to provide a machine-mallet which will deliver blows of varying strength upon the tool to which the mallet is applied.

My invention consists in the combination, with a rotating spindle carrying a spiral cam, of a mallet adapted to be engaged by the spindle, a spring for driving the mallet forward, a sleeve for application to the head of the tool, in connection with which the mallet is used, and an adjustable spindle for automatically varying the strength of the blow, all as will be hereinafter more fully described.

The casing A, which is preferably7 of cylindrical form,is made in three parts ab c. The parts a b are connect-ed by the bushing d and the part c, which is screwed into the part b, forms a shoulder e, which limits the outward motion of the sleeve f, placed in the said part c. The outer end of the part c is flared, forming a cup for receiving the end of the tool, in connection with which the mallet is used, and the end of the sleeve f is concaved for the same purpose. The sleeve fis bored in two diameters, the larger bore being adapted to receive the rod g, and forms a shoulder or seat s for the lower end of the rod g to liinitI its outward motion, while the smaller bore receives the rod 7l, which screws into the end of the rod g and projects beyond the concaved end of the sleeve f.

In the casing A is placed a mallet B, which is bored axially, through which and the bore in the bushing d the spindle C loosely passes. It is also counterbored upon one end to form a spring-chamber 0l and upon the other end is made a screw projection t, on which is formed the cam 7o, while a cam l is attached to the inner extremity of the spindle C. The chamber j is formed by a centrally-bored cap m, through which the rod g passes, and is counterbored and threaded internally as faras is necessary to be screwed onto the projection t. The remaining depth of the closed chamber 7' is just sufficient to allow the cani l to rest normally upon the conical end of the rod g and revolve freely backward and forward without touching the bottom of the chamber or the cam 7o. dle C and abuts upon the bushing d and central solid portion of the mallet B.

The outer extremity of the spindle C is provided with a carrier o, which tits loosely in the part a of the casing, and is adapted to be engaged by a clutch upon the end of a ilexible cord or other rotating device used in driving the spindle C. The mallet B is prevented from turning in the casing A by pins p, projecting from the side thereof into grooves q formed in the casing.

When the concave end of the sleeve f is applied to the end of a dental tool, such as is shown in Fig. (i, the end of the rod h is first engaged, pushing in the rod g, which is attached thereto, thus carrying the spindle C forward so as to bring the cam Zinto engage ment with the cam 7o as the spindle C is revolved. The amount of lift of the mallet B is regulated by the depth of contact of the cams k l. By unscrewing the rod h from the rod g the length of the two rods combined will be increased and the cam l will be carried farther in, so as to increase the lift of the mallet B. The litt of the mallet is decreased by reversing this operation. As the spindle C revolves, the engagement of the cam Z with the cam 7u lifts the mallet, and as the said cam Z passes the cam k the mallet is released, when the spring n will drive the mal- A spiral spring'n surrounds the spinlet forward against the sleeve f, delivering a blow upon it, which will be transmitted to the tool placed against the end of the sleeve.

By pushing the casing A of the machine forward in the direction of the tool the rods h g, the sleevef, the spindle C, and the mallet B will be forced inward against the pressure of the spring n, thus increasing the power of the spring over the mallet and causing it to deliver a heavier blow.

It will thus be seen that the lift of the mallet, and consequently its stroke, is regulated by means of the rod 7l., While the strength of the blow is controlled automatically in the manner described by increasing or diminishing the pressure of the mallet upon the tool to which it is applied.

Having thus described my invention, I claim as new and desire to secure by Letters Patent-- l. In a machinc-mallet, the combination, with a spring-pressed mallet having a cam projection, of a lon gitndinally-sliding and revoluble cam normally held out of engagement with the cam projection of the mallet., and means for bringing the revoluble cam into engagement with the said cam projection, substantially as described.

2. In a machine-mallet, the combination, with a spring-pressed mallet having a cam projection, ol a longitndinallysliding and revoluble cam normally held out of engagement with the cam projection of the mallet, and a sliding rod engaging the said cam and adapted to force the cam into engagement with the cam projection of the mallet when the tool is in use, substantially as described.

3. In a machinc-mallet, the combination, with a spring-pressed mallet having a cam projection, of a longitudinally-sliding and revoluble cam normally held ont of engagement with the cam projection of the mallet, and a rod formed of sections adjnstably connected together and adapted to engage the revoluble cam and to be engaged by the tool to force the said cam into engagement with the cam projection ot the mallet, substantial] y as herein shown and described.

4. In a machine-manet, the combination of the casing A, the spindle C, provided With the spiral cam l, the chambered mallet B, having the cam 7a, the spiral spring u., the rods g h, for moving the cam Z into engagement with the cam 7c, and the sleeve f, for receiving the blow of the mallet I3 and transmitting the blow to the tool in Contact with the end of the sleeve, substantially as specified.

5. In a machine-mallet, the combination, with a casing having a flaring end, of a springpressed mallet having a cam projection, a sliding and revoluble cam normally held out of engagement with the cam projection of the mallet, an apertu red sleeve against which the mallet strikes, and a rod littingin the aperture of the sleeve and engaging the-revoluble cam and adapted to be pushed inward bythe tool, being used to force the cam into engagement with the cam projection of the mallet, substantially as herein shown and described.

JOSEPH L. MEXVBORN.

\Yit11esses:

EDWARD F. ADAMS, Rans P. (VYARY. 

